The dental restoration of a partially or wholly edentulous patient with artificial dentition is typically done in two stages. In the first stage, an incision is made through the gingiva to expose the underlying bone. An artificial tooth root, usually a dental implant, is placed in the jawbone for integration. The dental implant generally includes a threaded bore to receive a retaining screw holding mating components therein. During a typical first stage, the gum tissue overlying the implant is sutured and heals as the osseointegration process continues.
Once the osseointegration process is complete, the second stage is initiated. Here, the gum tissue is re-opened to expose the end of the dental implant. A healing component or healing abutment is fastened to the exposed end of the dental implant to allow the gum tissue to heal therearound. In addition to and separate from the healing abutment, an impression component is fitted onto the exposed end of the implant. This allows an impression of the region of the patient's mouth to be taken so that an artificial tooth is accurately constructed. Preferably, the impression coping has the same gingival dimensions as the healing component so that there is no gap between the impression coping and the wall of the gum tissue defining the aperture. The impression coping may be a “pickup”-type impression coping or a “transfer”-type impression coping, both known in the art.
After these second stage processes, a dental laboratory creates a prosthesis to be permanently secured to the dental implant from the impression that was made. In doing so, the impression coping is located within the impression material and an implant analog is attached to the impression coping. The implant analog replicates (i.e., is “analogous” to) the dental implant that is located within the patient's mouth.
In many instances, the laboratory prefers to have a soft tissue model that replicates the patient's gingival tissue located at the region within the impression that corresponds to the location of the patient's gingival tissue. Thus, the soft tissue model is developed from modeling material placed in the impression around the implant analog. The stone model material is then poured into the impression that includes the soft tissue modeling material and allowed to harden. Once the impression material is removed from the soft tissue model and the stone model, the laboratory can then begin to fashion the final prosthesis on the implant analog.
The laboratory will often want to remove the soft tissue model from the stone model. For example, the laboratory technician may want to visualize the subgingival contours of the dental prosthesis, but cannot do so if the soft tissue model is present. When reinstalling the soft tissue model back onto the stone model, the soft tissue model is simply slid over the implant analog. In prior art implant analogs, however, there is nothing that registers the appropriate location of the soft tissue model on the implant analog or the stone model. Because it is desirable to maintain registration of the soft tissue model on the stone model as accurately as possible, many laboratories will often glue the soft tissue model onto the stone model to hold it in place. When the soft tissue model is removed from the stone model, the glue is removed from the stone model and new glue is added upon reinstalling. This registration problem is accentuated when the laboratory technician is developing a single tooth restoration having very little surface area between the soft tissue model and the stone model for providing registration and between the soft tissue model and the analog.